Human spinal columns comprise an upper portion having in excess of 20 individual bones, and a lower portion comprising the sacral bone and the coccygeal bodies. Scoliosis is a medical condition in which an individual's spine becomes curved from side to side, laterally, and becomes shaped like a “C” or an “S”. The spine can also rotate about its vertical axis. This is a very painful condition in adults. Scoliosis is typically classified as congenital (caused by vertebral anomalies at birth), idiopathic (sub-classified as infantile, juvenile, adolescent or adult according to when onset occurs) or as having developed as a secondary symptom of another condition, such as spina bifida, cerebral palsy, spinal muscular atrophy or due to physical trauma.
While the most common form of scoliosis is adolescent idiopathic scoliosis, there is no clear common cause. Scoliosis, when present in an individual, worsens during the adolescent growth spurt. Also, during adolescence, due to rapid growth of the body, hip and leg proportions in the leg and thigh may become misaligned, causing temporary scoliosis. If left untreated, scoliosis can be very painful in adulthood due to the muscles trying to conform to the abnormal curvature of the spine.
While doctors do not always recommend surgery as the treatment for scoliosis, it is the most efficient method of straightening the spine. Scoliosis surgery may be performed for cosmetic reasons rather than to relieve or prevent pain. Spinal fusion is currently the most widely performed surgery for the treatment of scoliosis. This technique may be performed from the anterior (front) of the spine, from the posterior (back) of the spine or a combination of anterior and posterior. The goals of this surgery include stabilization of spinal segments (i.e. vertebrae), deformity correction within safe parameters and enhancement of spinal fusion. One of the techniques employed in spinal fusion utilizes pedicle screws inserted into the vertebrae, and stabilization rods secured to and spanning a plurality of pedicle screws.
Other types of problems related to the human spine include injury or deterioration of the discs located between the vertebrae. One procedure to correct these problems is to remove the damaged or deteriorated discs and fuse adjacent vertebras together. This procedure is similar to the treatment of scoliosis, but it involves a smaller number of vertebrae. Pedicle screws and stabilization rods are employed in this procedure also.